Social implications of human food subsidies on wildlife populations

Abstract

Human activities generate a variety of novel food sources that wild animals exploit. On land and in water, these human-derived foods can profoundly alter intraspecific interactions in wildlife with cascading effects on population dynamics and ecosystem functioning. Yet, despite their growing ecological relevance, the role of human food subsidies in shaping intraspecific interactions remains underexplored. We propose a novel framework that captures how key characteristics of human food subsidies-such as high abundance, predictability, increased proximity to humans and dietary composition-modify social interactions. Specifically, we discuss how individual-level changes in fitness, time allocation, movement and social choices can shape interactions and the resulting social network properties, both directly and indirectly through alterations in population size, density and composition. Finally, we outline the ecological and evolutionary consequences of these social changes, including impacts on the transmission of diseases, stress and information, as well as on selection and development. Collectively, these alterations highlight the broad social implications that intentional and unintentional human food subsidies can have for ecological and evolutionary processes in wildlife populations.